鄂尔多斯盆地新安边地区长7页岩油储层孔隙结构特征  

Characteristics of pore throat structure of Chang 7 shale oil sandstone reservoir in the western Xin'anbian area,Ordos Basin,China

作　　者：肖玲 胡榕[1,2] 韩永林 雷宁 陈曦 XIAO Ling;HU Rong;HAN Yonglin;LEI Ning;CHEN Xi(School of Earth Science and Engineering, Xi'an Shiyou University, Xi'an 710065, China;Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi'an Shiyou University, Xi'an 710065, China;Department of Development, PetroChina Changqing Oilfield Company, Xi'an 710018, China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]西安石油大学陕西省油气成藏地质学重点实验室,西安710065 [3]中国石油长庆油田分公司油田开发事业部,西安710018

出　　处：《成都理工大学学报（自然科学版）》2022年第3期284-293,共10页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家科技重大专项(2016ZX05056);陕西省教育厅科研计划项目(21JK0839);西安石油大学研究生创新与实践能力培养项目(YCS21112044)。

摘　　要：研究鄂尔多斯盆地新安边地区西部上三叠统延长组长7页岩油砂岩储层渗流能力与孔隙结构之间的关系。采用铸体薄片、扫描电镜、高压压汞、恒速压汞及核磁共振等测试技术,对新安边地区西部长7页岩油储层的物性、孔隙结构进行定性-定量研究。结果表明:长7储层的主要储集砂体类型为浊流砂体及三角洲前缘砂体,以长石砂岩、岩屑长石砂岩为主,粒度较细,储层致密、面孔率低,粒间孔及长石溶孔为最重要的孔隙类型;长7储层具有排驱压力较大、中值压力大、中值半径小等特点;不同物性储层的孔隙大小及分布差异不大,但喉道大小及分布差异相对较大;储层中纳米级喉道和亚微米级喉道控制着可动流体,随着渗透率的增大,开发潜力增大。长7储层孔隙结构的多样性及不均一性是导致储层非均质性的主要原因,浊流砂体的孔隙结构好于三角洲前缘砂体,喉道半径控制着储层的渗流能力。Based on the analyses of casting thin sections,scanning electron microscopy(SEM),high-pressure mercury injection and constant velocity mercury injection test and nuclear magnetic resonance(NMR)technology,the physical property and pore structure of Chang 7 shale oil sandstone reservoir in Yanchang Formation of Upper Triassic are studied quantitatively and qualitatively in order to understand the relationship between seepage capacities.The results show that the main reservoir sand bodies of Chang 7 reservoir are turbidite sand bodies and delta front sand bodies,mainly composed of arkose and lithic arkose,with fine grain size,dense reservoir and low face rate.Intergranular pores and feldspar dissolved pores are the most important pore types.Chang 7 reservoir is characterized by large displacement pressure,large median pressure and small median radius.There is little difference in pore size and distribution in Chang 7 reservoirs with different physical properties,but the difference in throat size and distribution is relatively large.Nanoscale throats and submicron throats control movable fluid in Chang 7 reservoir.The development potential of reservoir increases as the permeability increase.It is considered that the diversity and heterogeneity of pore structure in Chang 7 reservoir are the main causes of reservoir heterogeneity.The pore structure of turbidity current sand body is better than that of delta front sand body,and the throat radius controls the seepage capacity of reservoir.

关 键 词：孔隙结构 喉道半径 页岩油储层 延长组 鄂尔多斯盆地 

分 类 号：TE122.23[石油与天然气工程—油气勘探]